Preprints
Filtering by Subject: Engineering
Landscape classification with deep neural networks.
Published: 2018-06-19
Subjects: Computer and Systems Architecture, Computer Engineering, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geology, Geomorphology, Other Statistics and Probability, Physical Sciences and Mathematics, Statistics and Probability
The application of deep learning, specifically deep convolutional neural networks (DCNNs), to the classification of remotely sensed imagery of natural landscapes has the potential to greatly assist in the analysis and interpretation of geomorphic processes. However, the general usefulness of deep learning applied to conventional photographic imagery at a landscape scale is, at yet, largely [...]
Surface albedo as a proxy for land-cover clearing in seasonally dry forests: evidence from the Brazilian Caatinga
Published: 2018-05-17
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Other Environmental Sciences, Physical Sciences and Mathematics
Ongoing increase in human and climate pressures, in addition to the lack of monitoring initiatives, makes the Caatinga one of the most vulnerable forests in the world. The Caatinga is located in the semi-arid region of Brazil and its vegetation phenology is highly dependent on precipitation, which has a high spatial and temporal variability. Under these circumstances, satellite image-based [...]
Rainfall-Runoff modelling using Long Short-Term Memory (LSTM) networks
Published: 2018-05-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydrology, Physical Sciences and Mathematics
Rainfall-runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data driven models. In this paper, we propose a novel data driven approach, using the Long-Short-Term-Memory (LSTM) network, a special type of recurrent neural networks. The advantage of the LSTM is its ability to learn long-term [...]
Strain analysis of a seismically-imaged mass-transport complex, offshore Uruguay
Published: 2018-04-23
Subjects: Earth Sciences, Engineering, Geology, Life Sciences, Physical Sciences and Mathematics
Strain style, magnitude, and distribution within mass-transport complexes (MTCs) is important for understanding the process evolution of submarine mass flows and for estimating their runout distances. Structural restoration and quantification of strain in gravitationally-driven passive margins have been shown to approximately balance between updip extensional and downdip compressional domains; [...]
Climatic influences on the offset between d18O of cave drip waters and precipitation inferred from global monitoring data
Published: 2018-03-09
Subjects: Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Speleology
We present a meta-analysis of data from 22 caves and 96 drip sites from 4 continents where both the cave drip water d18O and the weighted mean d18O of precipitation have been measured. Drip water d18O is similar to the weighted mean d18O of precipitation (within ± 0.3 ‰) for sites where mean annual temperature (MAT) is less than 15 °C (85% of drips where MAT < 15 °C) and an aridity index [...]
Communicating Unnatural Disasters
Published: 2018-01-03
Subjects: Earth Sciences, Engineering, Environmental Studies, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
Off the back of the 2017 hurricanes we extend the notion of human-influenced meteo-hydro hazards to include deeper geophysical events. We question where to place Human responsibility in a changing world, and we outline ways to bridge the gaps between scientist’s technical knowledge and ‘meaning’ as it is understood by people at risk. This short Op-ed has been rejected by Science after two rounds [...]
Submarine salt dissolution in the Santos Basin, offshore Brazil
Published: 2017-12-30
Subjects: Engineering, Other Engineering
Salt dissolution occurs when evaporite-dominated rocks come into contact with NaCl-undersaturated fluids. Salt dissolution can positivity and negatively impact hydrocarbon and mineral exploration, seismic imaging, drilling, and structural restorations in salt-bearing sedimentary basins. However, due to typically poor seismic imaging and a lack of borehole data, few studies have analysed the [...]
The role of glacier retreat for Swiss hydropower production
Published: 2017-12-22
Subjects: Earth Sciences, Engineering, Environmental Sciences, Glaciology, Hydrology, Natural Resource Economics, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sustainability, Water Resource Management
High elevation or high latitude hydropower production (HP) strongly relies on water resources that are influenced by glacier melt and are thus highly sensitive to climate warming. Despite of the wide-spread glacier retreat since the development of HP infrastructure in the 20th century, little quantitative information is available about the role of glacier mass loss for HP. We provide the first [...]
Optimising tidal range power plant operation
Published: 2017-12-11
Subjects: Civil and Environmental Engineering, Civil Engineering, Computational Engineering, Electrical and Computer Engineering, Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Power and Energy
Tidal range power plants represent an attractive approach for the large-scale generation of electricity from the marine environment. Even though the tides and by extension the available energy resource are predictable, they are also variable in time. This variability poses a challenge regarding the optimal transient control of power plants. Here we consider simulation methods which include the [...]
Characterising Drainage Multiphase Flow in Heterogeneous Sandstones
Published: 2017-12-07
Subjects: Earth Sciences, Engineering, Hydrology, Physical Sciences and Mathematics
In this work, we analyse the characterisation of drainage multiphase flow properties on heterogeneous rock cores using a rich experimental dataset and mm-m scale numerical simulations. Along with routine multiphase flow properties, 3D sub-metre scale capillary pressure heterogeneity is characterised by combining experimental observations and numerical calibration, resulting in a 3D numerical [...]
Comparison of 0-D, 1-D and 2-D model capabilities for tidal range energy resource assessments
Published: 2017-11-22
Subjects: Civil and Environmental Engineering, Computational Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Sciences, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Power and Energy
Tidal range energy projects present an attractive means for the predictable and large-scale generation of electricity from the marine environment. In particular, proposals are under consideration in UK waters, with their feasibility currently being under high levels of scrutiny. This is due to a combination of potential environmental and socio-economic impacts that are challenging to quantify in [...]
A comparison of GPS, VLBI and model estimates of ocean tide loading displacements
Published: 2017-11-14
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics
In recent years, Ocean Tide Loading Displacements (OTLD) have been measured using the Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI). This study assesses the accuracy of GPS measurements of OTLD by comparison with VLBI measurements and estimates derived from numerical ocean tide models. A daily precise point positioning (PPP) analysis was carried out on ~11 years of [...]
GPS sidereal filtering: coordinate- and carrier-phase-level strategies
Published: 2017-11-14
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Other Civil and Environmental Engineering, Other Earth Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Multipath error is considered one of the major errors affecting GPS observations. One can benefit from the repetition of satellite geometry approximately every sidereal day, and apply filtering to help minimize this error. For GPS data at 1 second interval processed using a double-difference strategy, using the day-to-day coordinate or phase residual autocorrelation determined with a 10 hour [...]
Using filtered and semi-continuous high rate GPS for monitoring deformations
Published: 2017-11-14
Subjects: Civil and Environmental Engineering, Civil Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Geotechnical Engineering, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Structural Engineering
Multipath is a major sidereally-repeating error affecting precise GPS positioning and deformation monitoring. Because satellite-receiver geometry repeats almost exactly every sidereal day, filtering can reduce multipath in near-static situations. Here, we investigate how sidereal filtering can be used in a switched multi-antenna array system providing semi-continuous GPS data, which may be [...]
An examination of network RTK GPS services in Great Britain
Published: 2017-11-14
Subjects: Civil and Environmental Engineering, Civil Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
As of March 2009, network real-time kinematic (RTK) GPS surveying is available in Great Britain with the aid of two commercial service providers, Leica’s “SmartNet” and Trimble’s “VRS Now”, both of which rely largely on the Ordnance Survey’s “OS Net” network of around 120 continuously operating reference stations. With the aim of testing the performance of Network RTK under both ideal and [...]